*2.2. Review of Selected Real Case VPP Realizations*

Despite the many investigations concerning VPP concepts, strategies and control, it is worth noticing actual VPP projects, which show the scale of developments and results:

• The Fenix project was developed to improve the contribution of distributed energy resources to the electric network by aggregating them into Large Scale Virtual Power Plants. The project is based on the cooperation of DG owners, energy companies, research institutes and universities—EDF, Areva, Siemens, ECRO SRL, Imperial College London, the University of Manchester and the University of Amsterdam, among others. The project consists of three phases [46]. The first phase involves the preparation of two scenarios—northern and southern—which are described in this subsection. The analysis presented in paper [46] included the DER contribution to the network, as well as its strengths and weaknesses. The second phase covered the design of the communication and

control system between the DERs in a VPP. The last phase concerned the validation of previously prepared analysis and systems through the realization of building 2 installations—in the UK and Spain [47]. Close to Bilbao City in Spain, there is a FENIX Southern Demonstration VPP connected to the Iberdrola system. The indicated installation connect a lot of different DER, such as combined heat and power (CHP), wind turbines, hydropower, photovoltaics, a CHP-biomass system, with a combined total capacity of 0.168 GW. The distribution area, that the project is realized has the peak demand equal to 0.320 GW. It works as a casual VPP. It means, that information from every connected distributed energy source is analyzed in the main control system. The information is exchanged in an intelligent interface called "FENIX Boxes." This system connects every DG. The indicated intelligent electronic devices assures adequate steering and implementation for the communication protocols. The protocols use wireless communication approaches for the distributed energy sources and control systems. It is based on the Virtual Private Network. The Virtual Private Network unites the heat and power plants, wind and solar sources and heat pumps, which assures creation of the interconnected, flexible system that has centralized control.

